The present invention relates to a biosensor for use in determining the concentration of an analyte in a sample.
Electrochemical biosensors are known. They have been used to determine the concentration of various analytes from biological samples, particularly from blood. Biosensors are described in U.S. Pat. Nos. 5,288,636; 5,413,690; 5,762,770; 5,798,031; and 5,997,817, the disclosure of each of which are expressly incorporated herein by reference.
It is known to emboss a lid formed of a deformable material to form a concave area that acts as a capillary space into which a fluid test sample can be drawn. See, for example, U.S. Pat. No. 5,759,364. It is also known to form a capillary gap between opposing surface areas spaced apart by a spacer layer. See, for example, European Patent Appln. 0 287 883 to Miles Inc. and U.S. Pat. No. 5,141,868.
According to the present invention, a biosensor is provided that forms a capillary channel between a cover and substrate, without the aid of a spacer or the additional manufacturing step of embossing either the cover or the substrate. The biosensor comprises a substrate, a reagent positioned on the substrate, and a cover including a top side and a generally flat bottom side. The bottom side is coupled to the substrate to define a sealed portion and an unsealed portion. The unsealed portion cooperates with the substrate to define a channel extending across the reagent.
In addition, according to the invention a biosensor is provided that comprises a substrate, a reagent positioned on the substrate, and a cover having a top side and a generally flat bottom side, and an opening extending between the top and bottom sides. The bottom side is coupled to the substrate to define a sealed portion and an unsealed portion. The unsealed portion cooperates with the substrate to define a channel extending between the opening and the reagent.
Further, according to the invention a method of forming a biosensor having a capillary channel is provided. The method comprises the steps of providing a substrate, providing a cover having a top surface and a bottom surface, placing a thermoset adhesive on the bottom surface of the cover, placing the adhesive-coated bottom surface on the substrate, and heating portions of the thermoset adhesive to couple the bottom side to the substrate to define a sealed portion and an unsealed portion. The unsealed portion cooperates with the substrate to define a channel extending across the reagent.
Additional features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.